The present invention relates to stimulation electrodes whose porous layer is partially coated with an insulating film.
According to U.S. Pat. No. 6,501,994, parylene (polyparaxylylene) is a preferred coating material. For creating a partial coating, U.S. Pat. No. 6,501,994 teaches the application of masks and their later removal. Here, a problem in the removal of the resist is that the parylene film always bleeds during the removal of the mask, and therefore does not lead to reproducible partial coatings, or the porous film is damaged by the mask or its removal. Standing against an inverse procedure, namely a fall-surface coating with parylene and subsequent partial removal, is that when the parylene film is removed, the porous layer located underneath is usually damaged and the high capacity achieved with difficulty by way of the porous layer would be undone.